A thick sludge made from food scraps and sewage to create methane gas could soon become a viable source of renewable energy.

The new technology, which depends on mixing pulped fruit and vegetable scraps with wastewater, will soon be trialed at an Australian plant.

A sewage treatment centre in Cronulla, in Sydney's south, already generates about 50 per cent of its own power, but the food sludge is set to give the current process a boost.

Sludge made from food waste will be used to help create power at Cronulla Wastewater Treatment Plant

It's thought more than 60 per cent of the energy needs at Cronulla Wastewater Treatment Plant in Sydney's south will be generated the technology.

The trial could lead to the renewable energy technology being used elsewhere in the state.

'The energy that we save here (the 60 per cent) would be equivalent to the energy that about 800 to 1000 homes would use every year,' Environment Minister Mark Speakman said at the launch of the three-year trial on Monday.

'If this works here ... we'll look at rolling it out elsewhere up and down the coast of NSW.'